2008 Establishing Permanent Transects for Monitoring Seed Dispersal by Clark’s Nutcrackers

Project: Establishing permanent transects for monitoring seed dispersal by Clark’s nutcrackers (Nucifraga columbiana) in relation to whitebark pine (Pinus albicaulis) health in Yellowstone, Grand Teton, Glacier, and Waterton Lakes National Parks

Agency/Forest or Park/District: Yellowstone, Grand Teton, Glacier, and Waterton Lakes National Parks

Project coordinator:  Diana Tomback

Contact: Diana F. Tomback, Ph.D.  Department of Biology, University of Colorado Denver, (303) 556-2657, Diana.Tomback@ucdenver.edu


Dan Reinhart, Yellowstone National Park, partner (307) 344-2145, dan_reinhart@nps.gov

Kelly McCloskey, Grand Teton National Park, partner (307) 739-3678, kelly_mccloskey@nps.gov

Sallie Hejl, Glacier National Park, partner (406) 888-7863, sallie_hejl@nps.gov

Cyndi Smith, Waterton Lakes National Park, partner (403) 859-5137, cyndi.smith@pc.gc.ca

All park partners will help identify potential trails or roads for transect placement; when possible, partners will join the team in the field to help establish or survey transects.

Additional cooperators:

Shawn McKinney, University of Montana, (406) 243-5297, shawn.mckinney@mso.umt.edu

Tara Carolin, Glacier National Park, (406) 888-7919, tara_carolin@nps.gov

Reese Halter, Global Forest Science, (760) 341-0779, rhalter@globablforestscience.org

Shawn McKinney has provided invaluable consultation on protocol and is interested in working in the field with us when he is able next summer.  Tara Carolin, vegetation specialist, has conducted restoration and monitoring activities for whitebark pine in Glacier National Park and previously coordinated Shawn McKinney’s research in the Park.  Reese Halter has been a long-time advocate of studies of nutcracker populations in view of the whitebark pine decline, and has offered to provide some support for this endeavor through the non-profit that he directs, Global Forest Science.

Source of funding

FHP: $12,311

Supplemental funding: $33,338 from CU Denver, RM-CESU, RM-NPS-Univ. of Montana: Jerry O’Neal fellowship, Global Forest Science tuition award.

Dates of restoration efforts

Summer 2008 and 2009


We request funding for field support to begin long-term monitoring of Clark’s nutcrackers as follows:(1) set up 2 to 4permanent transects per national park designed to assess and monitor Clark’s nutcracker numbers and seed dispersal activity in Yellowstone, Grand Teton, Glacier, and Waterton Lakes National Parks; (2) gather information on forest health, cone production, and pine regeneration; (3) monitor the transects in July and September 2008; and (4) obtain additional information on nutcracker stand use and seed dispersal in 2008.  We intend to resurvey these transects and gather additional observations in 2009, and then use this information to finalize the development of annual monitoring protocols that would assess nutcracker activity associated with possible dynamics of whitebark pine health.

Acres/ha treated  N/A


The UCD field team (Graduate Research Assistant Lauren Barringer, Undergraduate Research Assistant Kathryn Chipman, and P.I. Diana Tomback), in consultation with each National Park Cooperator, will establish 4 permanent 2 km x 30 m belt transects through stands of mature whitebark pine in Yellowstone National Park; 2 transects in Grand Teton National Park; 3 transects in Glacier National Park; and 2 transects in Waterton Lakes National Park prior to August 3, 2008.  The ends of the transects will be permanently marked with rebar stakes or tree tags, and described with geospatial coordinates, landmarks, and designated using GIS on park topographic maps.  The transect pathway will be indicated with special tree tags; and, the transect itself will be surveyed according to a protocol developed by Tomback in consultation with park cooperators and research cooperators.  No attempt will be made to randomize transect placement geographically, since we are using trails and roads for access, although transect starting points will be randomized.  All transects will be placed at least 25 m from a given road or trail.  Placement of transects will also be coordinated with existing park research and monitoring projects (e.g., whitebark pine cone transects, blister rust transects, etc.) to facilitate efficient sampling by park staff in subsequent years.

Whitebark pine seeds ripen in mid to late August, forming hard seed coats while cones become less resinous and scales open slightly.  Nutcrackers begin to fill their throat pouch with seeds at this time for transportation to caching sites, and this behavior, which is clearly observable in the field, may be equated with seed dispersal (Tomback 1978, 2001).  Before seeds ripen, nutcrackers act as seed predators rather than seed dispersers, and they shred cone scales as they remove seeds, leaving obvious signs of seed harvest (Tomback 1998).  In 2008 (and 2009), each 2 km x 30 m belt transect will be surveyed for nutcrackers twice in mid-to late July, before seed dispersal, and again twice in late August/early September after seed dispersal has begun.  Data collected will include the time of day the transect survey was started and ended; time of day, nutcracker sightings (with or without expanded throat pouch), nutcracker activities, nutcracker vocalizations without sightings, and squirrel sightings will all be recorded for 10 minutes at point count stops every 250 m (9 count stops).  These observations will be supplemented with similar information independent of point count stops, obtained as investigators walk each transect.  Nutcracker and other observations will be standardized as to mean number of activities per hour. Two permanent 50 m x 10 m subplots within each transect will be established to survey stand structure and composition, blister rust infection level and canopy damage, mountain pine beetle mortality, and whitebark pine regeneration, following methods developed by the Whitebark Pine Ecosystem Foundation www.whitebarkfound.org and modified by the Greater Yellowstone Whitebark Pine Monitoring Working Group.  The locations of the two subplots along a given transect will be randomized as follows:  Each 2 km transect will be divided into 200 m sections, and numbered in order (1 through10).  Using a random numbers table, two consecutive numbers in a row (0 to 9) will be selected, and these will represent the sections for subplot establishment.  In addition, within these two subplots, all whitebark pine trees will be surveyed for number of cones in mid-July and again in early September, as well as nutcracker foraging damage.  From these data, an estimate of initial and final cones per ha, and basal area per ha will be possible.  We recommend that these subplots be resurveyed every 3 to 5 years to assess stand health, but they must be surveyed every year in July and again in September for cone counts to compare with nutcracker observations.

Cone production in whitebark pine varies greatly from year to year, which will impact the numbers of nutcrackers observed on transects (e.g., McKinney and Tomback 2007).  For each permanent transect, the number of July and September estimated cones per hectare, estimated live basal area per hectare of whitebark pine, mean percent trees infected by blister rust, and mean canopy kill will be considered independent variables, and number of nutcracker observations per hour in July and then again in September the dependent variables.  Within a given year, these data will be compared both among transects within a park but also across parks for general trends; they will also be compared across years to elucidate the relationship between these variables and observed seed dispersal.

Additional nutcracker activities off-transect will be observed in July and September, as time permits, to learn more about tree preference, stand selection, seed caching, and movements. The kinds of data gathered will include dbh (diameter at 1.4 m) and cone count for whitebark pine trees with nutcracker-damaged cones; nutcracker numbers, activities; and, when nutcrackers are observed, we will gather data on stand composition and estimate cone abundance.  The nutcracker transects will be monitored again in July and September 2009 (pending funding).  As live whitebark pine basal area declines, canopy damage increases, and blister rust infection levels increase within subplots, we predict that nutcracker occurrence and seed dispersal activities will decline.

Planting? If so, source of seedlings? Resistance?  N/A


All proposed permanent transects were established, subplots were surveyed, and nutcracker point counts taken, as outlined in the original proposal.  The only data lacking are on individual tree preferences by nutcrackers.  The poor cone crop in 2008 summer coupled with a tight field schedule in late August precluded the team from gathering more data.  Point counts and cone counts will be repeated in 2009.  A better cone crop is predicted for summer, 2009 (and many conelets were apparent).

Main findings:

The highest density of whitebark pine, living and dead occurred in Yellowstone National Park, as well as the highest cone production.  The lowest density of whitebark pine occurred in Glacier National Park, with no cone production.  The highest tree mortality occurred in Grand Teton National Park and at Avalanche Peak in Yellowstone National Park.  These areas also had the highest proportion of trees killed by mountain pine beetle.  In contrast, both Waterton Lakes and Glacier National Parks had very high percentages of living trees with blister rust.  Most of the tree mortality in these two northern parks was caused by blister rust.  The healthiest stands of trees of all our study sites were along the Craig Pass transect in Yellowstone National Park.  There, mortality was in the single digits, with only one tree infected by blister rust and no mountain pine beetle mortality.

During the first round of nutcracker counts, Dunraven Pass in Yellowstone National Park and Teewinot Mountain in Grand Teton had the highest nutcracker counts (highest, n = 3), with the lowest counts at Avalanche Peak in Yellowstone National Park and in  Glacier National Park and Waterton Lakes National Park (n = 0 for all).  During the second round of counts, Teewinot Mountain again had the highest counts (highest, n = 10).  Aside from neighboring Amphitheatre Lake in Grand Teton, which had 0 birds, the transects in Glacier and Waterton Lakes National parks generally had the lowest counts (n=0).  In general, higher numbers of living whitebark pine and cone production predicted higher nutcrackers, but conclusive results await data analysis.

Miscellaneous comments

The  permanent transects’ length was shortened to 1 km.  Because most trails were from lower to higher elevations, a 2 km transect took us out of whitebark pine habitat.  Furthermore, NPS and  Parks Canada personnel are interested in continuing monitoring these transects, but wanted them very accessible and shorter than 2 km.